Commit 928df02b authored Sep 15, 2015 by James Hogan

metag: SMP: Fix 4KiB stack setup on secondary CPUs



Back in early 2008, 4KiB stack support was added to reduce memory
consumption on workloads with lots of threads, using a separate IRQ
stack per CPU to alleviate stack pressure. However the SMP code added a
year and a half later didn't set up the IRQ stack when bringing up
secondary CPUs, resulting in a crash when SMP is configured with 4KiB
stacks, as soon as the first interrupt arrived on a secondary CPU.

Fix with calls to irq_ctx_exit()/irq_ctx_exit() when bringing up/down a
CPU.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org

parent 6ff33f39

arch/metag/kernel/smp.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -312,6 +312,7 @@ void cpu_die(void)
	{		{
	local_irq_disable();		local_irq_disable();
	idle_task_exit();		idle_task_exit();
			irq_ctx_exit(smp_processor_id());

	(void)cpu_report_death();		(void)cpu_report_death();

	@@ -366,6 +367,7 @@ asmlinkage void secondary_start_kernel(void)
	panic("No TBI found!");		panic("No TBI found!");

	per_cpu_trap_init(cpu);		per_cpu_trap_init(cpu);
			irq_ctx_init(cpu);

	preempt_disable();		preempt_disable();